01 - Preheat the oven to 325°F. Grease a 9-inch springform pan and line the base with parchment paper.
02 - Combine the crushed chocolate sandwich cookies with melted butter until evenly moistened. Press the mixture firmly into the bottom of the prepared pan to create an even crust. Bake for 10 minutes, then set aside to cool slightly.
03 - Using an electric mixer, beat the softened cream cheese and granulated sugar on medium speed until completely smooth and free of lumps. Add the creamy peanut butter and sour cream, blending until fully incorporated.
04 - Add the eggs one at a time, mixing on low speed just until each egg is incorporated. Stir in the vanilla extract. Avoid overmixing to prevent excess air in the batter.
05 - Pour half of the cheesecake batter over the cooled crust. Drizzle half of the melted dark chocolate over the surface and gently swirl with a knife to create a marbled pattern. Add the remaining batter and repeat with the remaining melted chocolate.
06 - Bake for 50 to 55 minutes, until the edges are firmly set but the center still has a slight jiggle. Turn off the oven, crack the door open, and let the cheesecake rest inside for 1 hour as it gradually cools.
07 - Transfer the cheesecake from the oven to the refrigerator. Chill for at least 4 hours, or preferably overnight, until completely firm and set.
08 - Heat the heavy cream in a small saucepan until hot but not boiling. Pour it over the finely chopped dark chocolate and let stand for 2 minutes. Stir until a smooth, glossy ganache forms, then blend in the peanut butter. Spread the ganache evenly over the chilled cheesecake and allow it to set for at least 30 minutes before slicing.